Fiber optic cables are widely used for transmitting telecommunications signals. It is common to produce fiber optic cables for transmitting such signals by surrounding one or more optical fibers within a loose fitting buffer tube in order to isolate the fibers from bending and tensile stresses imparted on the cable. It is also known that the cable may be strengthened by including one or more steel strength members within the cable. Several prior patents have proposed cables comprising a number of optical fibers disposed loosely within a buffer tube and having at least one strength member outside the buffer tube and incorporated within the cable. For example, Dean et al. U.S. Pat. No. 4,420,220, Nilsson U.S. Pat. No. 5,029,974, and Arroyo et al. U.S. Pat. No. 5,138,685 disclose such cables.
In circumstances where telecommunications signals are transmitted over long distances, signal repeaters are used to boost the effective transmission distance of the cable. These signal repeaters are typically powered by electrical current. In an emerging telecommunications architecture, fiber optic cables are replacing more traditional copper facilities. The local telephone company typically provides power to a subscriber's telephone via the pair of copper wires which also carry the telecommunications signals. Accordingly, it may be desirable to distribute electrical power over a fiber optic cable either directly to a subscriber or to other electronics remaining along a copper portion of the network.
It is known that fiber optic cables can be produced in conjunction with electrical conductors in order to supply power to signal repeaters or other electronics. The electrical conductors may also be used to carry communication messages themselves. Barrett et al. U.S. Pat. No. 5,189,718 discloses the use of electrical conductors in conjunction with the fiber optic cable wherein the electrical conductors are contained within a separate tube attached to the tube containing the optical fibers.